Hypoglycemic effect of bitter melon compared with metformin in newly diagnosed type 2 diabetes patients 

In this randomized, double-blind, active control multi-center trial from 2011, researchers sought to define the minimum effective dose for bitter melon extracts for inducing a hypoglycemic effect as compared with metformin. One hundred and twenty-nine subjects were enrolled, all of which were newly diagnosed with type 2 diabetes. The study had 4 treatment arms: metformin 1000 mg/day (n=30), 500 mg/day bitter melon (n=31), 1000 mg/day bitter melon (n=30), 2000 mg/day bitter melon (n=29.) Key outcomes were the mean change in fructosamine from baseline to endpoint.  The authors found that 2000 mg/day of a bitter melon extract significantly reduced fructosamine levels (−10.2 micromol/L; 95% CI, −19.1 to −1.3), although not quite as much as the drug metformin (−16.8 micromol/L; 95% CI, −31.2 to −2.4). 

References:

Fuangchan A, Sonthisombat P, Seubnukarn T, Chanouan R, Chotchaisuwat P, Sirigulsatien V, Ingkaninan K, Plianbangchang P, Haines ST. Hypoglycemic effect of bitter melon compared with metformin in newly diagnosed type 2 diabetes patients. J Ethnopharmacol. 2011 Mar 24;134(2):422-8. doi: 10.1016/j.jep.2010.12.045. Epub 2011 Jan 4. PMID: 21211558. https://pubmed.ncbi.nlm.nih.gov/21211558/